[llvm] [VPlan] Fix crash when unrolling in-loop reduction chains (PR #129840)

[Florian Hahn via llvm-commits]

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@@ -295,8 +295,8 @@ void UnrollState::unrollRecipeByUF(VPRecipeBase &R) {
       continue;
     }
     if (auto *Red = dyn_cast<VPReductionRecipe>(&R)) {
-      auto *Phi = cast<VPReductionPHIRecipe>(R.getOperand(0));
-      if (Phi->isOrdered()) {
+      if (auto *Phi = dyn_cast<VPReductionPHIRecipe>(R.getOperand(0));
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fhahn wrote:

Multiple statements as part of the condition are very uncommon in most parts of LLVM AFAICT, so for consistency it would be good to avoid.

https://github.com/llvm/llvm-project/pull/129840